基于粗糙颗粒动理学流化床内颗粒与幂律流体两相流动特性的数值模拟研究

在颗粒动理学理论（KTGF）的基础上，通过引入表征粗糙颗粒摩擦和切向非弹性的切向弹性恢复系数β，以及综合反映颗粒平动和旋转运动脉动强度的颗粒拟总温e₀，结合输运理论建立了考虑颗粒旋转作用的颗粒相质量、动量和颗粒拟总温守恒方程。并在求解了同时具有平动和旋转运动的能量耗散和颗粒相应力等参数的前提下提出了颗粒相压力、剪切黏度和能量耗散等本构关系式以及边界条件，最终得出了粗糙颗粒动理学理论（KTRS）。通过改变液相的流变特性，分析了幂律流变模型中流动指数n和稠度系数K_l对流化床内流固两相流动特性的影响，模拟结果表明：随着流动指数和稠度系数的增大，液相湍动能耗散率逐渐增大，而颗粒相压力逐渐减小，颗粒旋转先增大后减小。

Numerical simulation of hydrodynamic characteristics of particles and power-law fluid in fluidized beds using kinetic theory of rough spheres

On the basis of the traditional kinetic theory of granular flow (KTGF), the tangential restitution coefficient β, which characterizes the surface friction and tangential inelasticity of rough particles, and the total granular temperature e₀, which synthetically reflects the fluctuating intensity of the translational and rotational motion of particles, are introduced. Combining with the transport theory, the conservation equations of particle phase mass, momentum and total granular temperature considering particle rotation are established. Under the condition of solving the parameters of energy dissipation and particle phase stress with both translational and rotational motions, the constitutive relations of solids pressure, shear viscosity and energy dissipation, as well as the boundary conditions, are proposed. Finally, the kinetic theory of rough spheres (KTRS) is obtained. By changing the fluid rheological properties, the effects of flow index n and consistency coefficient K_l in the power-law rheology model on the hydrodynamic characteristics in a fluidized bed are studied respectively. The simulation results show that with the increase of the flow index and the consistency coefficient, the energy dissipation rate of the liquid phase turbulence gradually increases, while the particle phase pressure gradually decreases, and the particle rotation increases first and then decreases.